1. Field of the Invention
The present invention is directed to a coupling for a corrugated conduit, and more particularly to such a coupling utilized as an attachment of an end of the corrugated flexible conduit to a device or fitting with which the fluid medium conveyed by the conduit is utilized.
2. Description of the Prior Art
Such couplings for the corrugated conduit or hose have been extensively utilized in gas conveying system as well as in other fluid conveying systems. A typical prior coupling for the corrugated conduit is shown in Japanese unexamined Patent Publication (KOKAI) No. 60-73193 in which the end of a corrugated conduit is clamped by a nipple and is inserted together therewith into a sleeve on one side of a main tubular body. A nut is threaded on the sleeve to have a collar at its end in abutting engagement with the rear end of the nipple for pressing the nipple together with the end of the conduit forwardly into the sleeve, forcing the latter into sealing engagement with an annular shoulder projecting radially inwardly of the tubular body. In this prior coupling, however, the nipple is shaped to have a circular external configuration relatively freely rotatable within the sleeve so that it tends to be rotated by the frictional force developed at the abutment between the nut and the nipple as the nut is rotated on the sleeve in advancing the nipple and the end of the conduit into the sleeve, thereby subjecting the conduit to twisting or kinking forces which would damage the conduit or render the subsequent procedures to be rather inconvenient.